Greenhouse NFT: A Quick Guide to the Nutrient Film Technique

The Nutrient Film Technique (NFT) is a hydroponic system where a thin, continuous film of nutrient solution flows through shallow channels, keeping plant roots moist while exposing most of them to air. This provides excellent oxygen delivery, which boosts growth and reduces water use by 70–90% compared to soil farming.

Why Use NFT in a modern Greenhouse?

Faster cycles – up to 10 lettuce harvests per year vs. 3–4 with drip irrigation.

Space efficiency – channels can be stacked vertically to maximise density.

Year‑round production – with greenhouse climate control, you can grow pesticide‑free produce in any season.

Key Design Rules

Slope: 1–3% to avoid waterlogging or dry roots.

Flow rate: 1–2 litres per minute per channel.

Reservoir: ¼–1 gallon per plant, to buffer pH and nutrient swings.

Backup pump: Essential – a failure can kill crops within hours.

Best Crops

Leafy greens (lettuce, spinach, kale)

Culinary herbs (basil, mint, parsley)

Strawberries (selected varieties)

Compact fruiting crops (e.g., micro‑dwarf tomatoes) are gaining popularity.

Watch Out For

Pump/ power failure – invest in redundancy.

Disease spread – recirculating water can rapidly pass pathogens; keep sanitation strict.

Clogging – vigorous roots can block narrow channels; inspect regularly.

NFT is simple but demanding. When designed and managed well, it delivers outstanding efficiency and quality – making it a top choice for modern greenhouse growers.